1. Field of the Invention
The invention relates to an AWG (Arrayed Wave Guide Grating) coupler for spectrally separating electromagnetic radiation that has various frequency or wavelength regions.
2. Description of Related Art
Such couplers are used in information processing and telecommunications engineering to separate signal-carrying optical bands of electromagnetic radiation of different wavelength.
Previous AWG couplers normally have the design illustrated in the left-hand half of FIG. 2, which takes up a relatively large area. Very small bending radii occur in part in the various arms of the previously known coupler, which respectively serve to produce optical path length differences, as a result of which emission losses and instances of influence on the effective refraction index which impair the performance properties of the coupler can occur.